Remote control system



Sept. 22, '1964 A. GERBER 3,149,568

REMOTE CONTROL SYSTEM Filed March 4, 1959 4 Sheets-Sheet 1 AA H a IIIIIIIII I HL asaaa zee z $$z ML Bt 5 Px Py Ua 1 1 Vx Vy Va Fig-.1

Ex Ey TEa I i I bra/Mr.- fit' 4 Sept. 22, 1964 A. GERBER 3,149,568 REMOTE CONTROL SYSTEM Filegi March 4, 1959 4 Sheets-Sheet 2 A. GERBER Sept. 22, 1964 REMOTE CONTROL SYSTEM 4 Sheets-Sheet 3 Filed March 4, 1959 Elsi mmfdr. flip-ed 49 5 Am r 5% Sept. 22, 1964 Filed March 4, 1959 Ma----i A. GERBER REMOTE CONTROL SYSTEM la ly 4 Sheets-Sheet 4 United States Patent 3,149,568 REMOTE CONTROL SYSTEM Alfred Gerber, Zurich, Switzerland, assignor to Fir-ma Contraves A.G., Zurich, Switzerland Filed Mar. 4, 1959, Ser. No. 797,203 Claims priority, application Switzerland Mar. '12, 1958 8 Claims. (Cl. 102-702) The present invention concerns a remote control system for missiles or projectiles, and more particularly to an electrical remote control system for missiles or the like containing an explosive charge and a detonator device therefor.

The missile may be for instance of the type which is rocket propelled, with armor piercing hollow charge, and which is provided with a trailing wire connection with a control installation so that electrical control signals can be transmitted from the control installation to the missile for correcting its trajectory in the direction of two coordinates (left-right and up-down). Whenever remote controlled missiles of this type are used it is hardly possible to entirely exclude the danger that due to technical trouble in the remote control installation, along the path of signal transmission, in the receiver and transducer equipment, or within the missile itself, or also due to human errors in handling the control system, the missile goes out of control or may even move in direction toward friendly army units instead of to the enemy.

It is therefore a main object of this invention to provide for a remote control system for missiles of the type set forth in which a safety control means prevents the detonator device from causing explosion of the charge in the missile unless this is desired.

It is another object of this invention to provide for a remote control system of the above described type in which the safety control means in the missile are actuated by a signal which is transmitted to the missile from the remote control installation so that the missile is not in armed condition unless an arming signal is transmitted to it.

In other words, the purpose of the system according to the invention is to enable an observer to place the missile in armed condition and to return it to its normal notarmed condition whenever desired. Normally, the missile is kept in non-armed condition. This should particularly be the case when in the entire control system any defects or disturbances should occur which interfere with the regular transmission of control signals. Should such disturbances occur after the missile has been placed into armed condition, then the safety control means must automatically return the missile to its non-armed condition. The operator or observer at the remote control installation must be in a position to release the arming signal only after he is convinced that the missile is moving toward the desired target. Even if subsequently any disturbance or irregularity is observed, the operator must be in a position to cancel the arming signal so that the missile is returned to its normal non-armed condition.

With above objects in view a remote control system for missiles containing an explosive charge and a detonator device therefor comprises, according to the invention, electrically operable impact detonator means within the missile; electric circuit means connected to said detonator means and including a source of electrical energy for actuating the detonator means; safety control means in circuit with the detonator means and movable between a normal position in which the circuit is interrupted, and an arming position in which the circuit is closed for actuating the detonator means; and transducer means for receiving an arming signal and for moving the safety control means into the arming positions thereof upon receiving an arming signal.

In a preferred embodiment of the invention the safety control means include a bafile or shield means which, in the non-armed condition of the missile, is positioned between the charge and a detonator cap or the like so that an ignition of the detonator cap, e.g. upon impact of the missile on a target, cannot effect explosion of the charge. If the detonator cap is provided with electrical actuating means for igniting the cap, then electrical control means can be arranged in the electrical circuit operating the detonator cap, this circuit being closed only when the above-mentioned bafile or shield device is in a position corresponding to the armed condition of the missile.

Electromagnetic means may be provided for causing the movement of the shield device into arming position and bias means may be provided for returning the shield device into non-arming position. For operating the electromagnetic means a transistor circuit may be provided for acting as an electronic control switch under the influence of a control signal, hereinafter called arming signal, which is transmitted to the missile from the control installation and is received by receiving means in the missile and thereby converted into an impulse or current operating the above-mentioned electromagnetic means.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic schematic illustration of a remote control system according to the invention showing diagrammatically a missile with its essential control parts and a remote control installation connected therewith;

FIG. 2 is a wiring diagram showing details of the circuit means in a missile;

FIG. 3 is a modified electrical circuit diagram for the electrical control means in a missile;

FIG. 4 is a diagram illustrating in the form of voltage versus time the voltage variations in certain parts of the circuits illustrated by FIG. 3; and

FIG. 5 is a schematic electrical diagram illustrating a remote control system for transmitting an arming signal and for putting the same into effect.

Referring now to FIG. 1, a missile G is connected by a trailing electrical wire or cable D with a control installation L located at or near the place from which the missile is fired. It may be assumed that the operator of the control installation L is able to observe the move ments of the missile G toward the desired target or obtains information about such observations, so that this operator may apply control movements Mx to the control lever of a transducer device Wx in case the trajectory of the missile is to be corrected in the direction of a coordinate X. Similarly, for carrying out corrections in a coordinate direction Y at right angles to X, the control lever of the transducer Wy is caused to carry out mechanical control movements My. The two control levers may be combined into one single control stick movable in two coordinate directions. The transducers Wx and Wy, respectively, convert the mechanical movements of the control levers into electrical control signals Ex and By, respectively, which are injected by a coupling device K1 into the line connection D leading to the missile G.

In the missile Gthe signals Ex and By are received from the line connection D by a decoupling means K2 by which they are segregated from each other. Ampli fier and transducer means Vx and Vy, respectively, convert these received signals into mechanical control forces Px and Py, respectively, for operating the steering means of the missile. The control installation L comprises a further transducer device Wa provided with a button control or a similar means for converting a mechanical control movement Ma into an electrical arming signal Ea which is also injected by the device K1 into the line connection D and is received in the missile by the decoupling means K2 and is then segregated in the form of an electrical arming signal Ea. The amplifier and transducer device Va converts the received arming signal Ea into a control voltage -Ua which is a direct current voltage and is applied to a transistor Ta acting as an electronic control switch means. It is to be understood, of course, that this negative potential applies to electrical ground of the missile G and is applied to the base-emitter circuit of the transistor Ta. It can be seen now that as long as the arming signal Ea is received and converted in the transducer Va the transistor Ta is in conductive condition so as to constitute a closed switch while it is in non-conductive condition like an open switch as long as no arming signal Ea is received.

The missile G contains an explosive charge, for instance an armor piercing hollow charge HL which is associated with a detonator cap Z1 adapted to be ignited electrically. The detonator means of the missile G comprise, in addition to the electrically operable detonator cap Z1, an igniting device, for instance, an ignitor pin St which is mounted movable in axial direction of the missile G so as to move into an operating position upon impact of the missile G on a target or other object. The ignitor pin St is shown in FIG. 1 in its normal position, from which it will move upon impact of the missile G into a forward position. A normally open igniting contact Zs is arranged adjacent to the ignitor pin St, one contact blade of the contact Zs being provided with a pin which slidably engages a cam portion of the ignitor pin St in such a manner that when the last mentioned pin moves forward the contact Zs is moved into closed position. The igniting contact Zs is part of a circuit comprising in series a battery Bt, the igniting contact Zs, a safety control contact As, the electrically operable detonator cap Z1 and the collector-emitter circuit of the transistor Ta. Therefore, the circuit for igniting the detonator cap Z1 cannot be rendered operative unless also the safety control contact As is closed and the transistor Ta is rendered conductive.

Connected in parallel with the switches Zs, As and the detonator Z1 is a solenoid Ma which is energized whenever the transistor Ta is rendered conductive by the arrival of an arming signal Ea.

The detonator cap Z1 is associated with a shielding device, preferably having the form of a sleeve Ha which is provided with a shank Aa which serves the double purpose of slidably supporting the shield Ha. and of acting as the core for the solenoid Ma. In addition, the shank Act is surrounded by a return spring Fa which tends to urge the shield Ha into the shown position in which the detonator cap Z1 is protected against acting, in-the case of ignition, on the charge HL.

Whenever the solenoid Ma is energized, the shank Aa is attracted in the direction to the left, as seen in FIG. 1, whereby the shield Ha is removed from its normal position in which the missile is in non-armed condition, into a position in which the Walls of the shield Ha do not separate the detonator cap Z1 from the charge HL which means that in the second position of the shield Ha the missile G is in armed condition.

The safety control switch As is normally in open position and one contact blade thereof is provided with a pin adapted to be in slidable engagement with a cam portion on the shield Ha. Whenever the shield Ha is moved by the energization of the solenoid Ma into its non-arming position, the safety control switch As is closed.

It can be seen now that upon arrival of an arming signal Ea the shield Ha is moved into the armed position whereby the safety control switch As is closed. As long as the arming signal Ea is being transmitted the missile G remains in armed condition. If now upon impact on an object the ignitor pin St moves forward the igniting contact Zs is closed and thereby the circuit of the detonator cap Z1 is likewise closed and the detonation thereof is effected so as to cause the explosion of the charge HL. If, however, the impact causes closing of the igniting contact Zs while the arming signal Ea is not being transmitted, then the safety control switch As remains in open condition so that no detonation can be caused by the impact of the missile G.

if desired, a second detonator cap Z2 may be provided and connected in parallel with the detonator cap Z1, and this second detonator cap Z2 may serve to explosively remove the head of the missile G.

The above description implies that not only the operation of the detonator cap Z1 by the igniting switch Zs depends upon the arrival of an arming signal Ea given when the operator at the control installation L desires to arm the missile G, but also that in case of defects or disturbances in the transmission system between the control installation L and the missile G no ignition or detonation can take place. Thus, the system according to the invention provides maximum safety against the possibility that the missile could cause any damage except when it reaches the intended target area.

FIG. 2 illustrates in greater detail a circuit which is essentially a portion of the circuit given in FIG. 1. The battery Bt and the solenoid coil Ma are shown in the same relation as before. However, in this case it is assumed that the arming signal is transmitted in the form of an alternating voltage Ua. This alternating voltage Ua is amplified by an amplifying transistor Tv and is then rectified by the transistor Ta from where the electrical energy is supplied to the solenoid Ma.

It is known and conventional to adjust spoiler flaps arranged on the wings or fins of the missile serving as steering means, by applying trains of periodic pulses and by suitable pulse-time modulation thereof. Accordingly, FIGS. 3 and 4 illustrate another possibility of transmitting an arming signal and to apply this signal to the safety control means of the missile.

The circuit diagram of FIG. 3 constitutes essentially an amplifier arrangement comprising transistors, for the purpose of obtaining a controlling direct current voltage -Ua which may then be applied in the same manner as explained in reference to FIG. 1 to the control transistor Ta for causing the arming of the missile G whenever a corresponding or suitable arming signal is transmitted to the latter.

In the following description of the operation of the arrangement according to FIG. 3 reference is simultaneously had to the voltage-time diagram of FIG. 4. Pulsetirne modulated impulse voltages Ulix and Uly are applied to the input terminals a and b, respectively. As is known, the consecutive impulses start in periodical intervals. However, the duration of the individual impulses is variable and their variation contains the information for causing movement of the above-mentioned steering means in the direction of coordinates x, respectively. This known direction control system is based on the principle that if the duration of the individual pulses is shorter than a predetermined normal or mean value, a correction is to be effected in the negative direction of the particular coordinate. If, however, the duration of the individual pulses is greater than said predetermined means value, then the correction is effected in the positive direction of the particular coordinate. Accordingly, in FIG. 4 the conditions are shown in the left half thereof, marked A, as prevailing when no arming signal is transmitted to the missile G, while the right half of the diagram, marked B, illustrates the conditions prevailing when an arming signal is transmitted.

If the above described conventional means for pulsetime modulation type direction control are available, then the diagram of FIG. 1 may be interpreted in such a manner that in the remote control installation L the symbols Mx and My, respectively, represent means for generating trains of impulses of uniform time interval while the elements Wx and Wy, respectively, represent means for changing the duration of the individual pulses so that the signal Ex would correspond to the pulse sequence Ulx and the signal Ey would correspond to the pulse sequence Uly. Then, the device Wa would serve to control the component K1 in such a manner that the pulse trains Ulx and Uly are shifted one against the other in phase so that they are ofiset against each other by an amount equal to i.e. one-half of the time interval between two consecutive pulses as is illustrated in the portion B of FIG. 4. The means for generating the trains of pulses and the means for shifting one train of pulses with respect to the other train of pulses are entirely known and do not form part of the present invention.

In a manner analogous to that described with reference to FIG. 1, the voltage pulses Ullx and Uly, respectively, are transmitted as steering signals to amplifier and transducer means, not shown in FIG. 3, but corresponding to the devices Vx and Vy, respectively, shown in FIG. 1, for the purpose of deriving therefrom mechanical control forces Px and Py, respectively, which control in the usual manner the steering means of the missile. It can be seen, therefore, that the diagram of a circuit according to FIG. 3 replaces essentially the circuit in FIG. 1 between the device K2 and the transistor Ta.

As has been stated above, the trains of pulses Ulx and Uly are subjected to pulse-time modulation only for the purpose of steering the missile in the desired direction. The pulse-time modulation is not used for the purpose of this invention and can be disregarded entirely. Nevertheless, a certain pulse time variation is shown in FIG. 4 in the diagram of the pulse trains Ulx and Uly, respectively. Actually, what is used for the purposes of this invention, is only the sequence of voltage spikes corresponding in time exactly to the leading flank of the individual pulses as indicated in the third and fourth row of the diagram of FIG. 4, the individual consecutive voltage spikes being spaced from each other exactly by the same time interval t which is the spacing of consecutive pulses in the pulse trains Ulx and Uly, respectively. The sequences of voltage spikes are designated UZx and UZy, respectively, in FIG. 4. It can be further seen from FIG. 4 that the voltage spikes U2x and UZy are synchronous with each other in the portion A of the diagram which corresponds to a condition where no arming signal is being given to the missile, while the voltage spikes UZx and UZy are offset or phase shifted by against each other in the right-hand portion B of FIG. 4 which corresponds to the condition that an arming signal is transmitted from the control installation L to the missile G.

The series of voltage spikes acts as trigger signals UZx and U2y, respectively, on the corresponding multi-vibrator stages diagrammatically illustrated in FIG. 3. Each trigger impulse U2x and UZy causes the corresponding multi-vibrator arrangement connected to the input terminals a and b, respectively, to generate an impulse as shown in the impulse series U3x and U3y, respectively. The duration of each one of the pulses in these pulse sequences is determined by the time constants of the RC elements R3 and C3, respectively, and amounts to approximately 55% of the pulse period t. As can be seen from the portion A of FIG. 4, the impulses of the two seriesU3x and U3y appear simultaneously and synchronously provided that no arming signal is intended to be given or is given. However, when it is intended to transmit an arming signal, and the pulse trains Ulx and Uly are phase shifted against each other, then the pulses U3x and U3y appear, as is indicated in the portion B of FIG. 4, alternatingly if compared with each other regarding time.

The pulse series U31: and U3y are superimposed upon each other in the switching transistor T3. As long as at least one of the voltages U3x or U3y is negative, the transistor T3 is in conductive condition so that the voltage U4 has the value 0. Duringthose fractions of time in which the voltages U3x and U3y are both simultaneously not negative (during the intervals between the pulses U3x and= U3y in the portion A of FIG. 4), the transistor T3 is non-conductive and therefore the voltage U4 abruptly assumes the value U0 as illustrated at d in FIG. 4.

Consequently, as long as no arming signal is transmitted,

the voltage U4 will consist of periodic pulses Uo as shown in the portion A of FIG. 4. However, if and when an arming signal is received, the voltage U4 is kept continuously at the value 0 as shown in portion B of FIG. 4, because in this case at all times one of the two voltages U3x and U3y is negative.

The transistor T4 is also arranged as a switching transistor and is in conductive condition as long as the voltage U4 has the value '--Uo, but it is in non-conductive condition when the voltage U4 changes to 0. In the collector circuit of the transistor T4 is connected a delay circuit comprising a resistor R5 and a storage condenser C5 connected parallel therewith. As soon as the transistor T4 becomes conductive, the voltage U5 abruptly assumes the value 0 because the current charging the condenser does not meet any resistance in the transistor T4 because the latter is in conductive condition. However, during the transition from a conductive condition to a non-conductive condition of the transistor T4, the voltage U5 only gradually changes from 0 toward the value U0 because initially the discharge current of the condenser C5 flowing across the resistor R5 counteracts this change of voltage. The time constant of the delay circuit RSCS is so chosen that in the case where no arming signal is being transmitted or received (portion A of FIG. 4) i.e., when the transistor T4 is periodically rendered conductive (impulses U4), the discharging process of the condenser C5 cannot proceed to the point where its recharge starts again. As long as the potential US is more positive than the fixed and. predetermined reference potential UOR6 R6+R7 the comparator transistor T5 is in non-conductive condition so that no current can flow through its collector circuit containing the resistor R8 and the voltage Ua remains at the value 0. However, when no impulses U4 serves as the arming signal for the arrangement of FIG. 1.

It is easy to understand, the required control voltage -Ua can only be obtained if both impulse sequences Ulx and Uly having the relative phase shift to serve as an arming signal are properly received by the receiving "means of the missile G. If only one or both of these impulse sequences do not arrive as, for instance, due to a damage to the connecting line D or if the phase shift serving as an arming signal is not being applied to the direction control impulses, the control voltage --Ua cannot be generated so that the safety control device of the missile remains in non-arming position or is automatically moved back into this position.

A comparatively simple remote control system is illustrated diagrammatically in FIG. 5. In this system the remote control installation L is connected with the missile G by a four-wire connection D, the individual wires being marked Dx, Dy Da and Dr. The three signal transmitting wires Dx, Dy and Da are connected in the missile to the bases of the corresponding transistors Tx, Ty, Ta, respectively, the emitters of these transistors being connected to or ground of the missile, while the collectors of these transistors are connected via resistors Rx, Ry, Ra, respec tively, to the terminal U0 of the missile. It is evident that the above mentioned transistors can only operate if currents flow into them from the connecting wires Da, Dy, Dx, respectively, to their respective bases in the direction marked by arrows in the above mentioned connecting lines. If this condition prevails, then the base currents flowing in said direction produce signals Ex, By and Ea, respectively, of which the two first mentioned ones are being used for direction control of the missile, while the last-mentioned signal is used as an arming signal. Base currents flowing in opposite direction remain without efiect.

A direct current source BL is provided in the control installation L, one pole of this source being connected via resistors Qx, Qy, Qa, respectively, to the wires Dx, Dy, Da, respectively, while the opposite pole is directly connected to O and in this manner to the wire Dr and this line is connected in the missile also to the 0 terminal thereof and serves in this manner as a return lead for all signals transmitted to the missile.

' In the control installation L three transducer devices, illustrated in the form of control means acting as switches Wx, Wy, Wa, are provided for transmitting the direction control signal Mx, My, respectively and the arming signal Ma, the switches just mentioned being connected between the general conductor 0 and the line connections 1x, 1y, 1a, respectively. The individual switches Wx, Wy, Wa are actuated mechanically by means indicated by the symbols Ma, My, Mx, respectively. The switches Wx, Wy are normally open and are closed for the purpose of transmitting impulses only periodically for a shorter or longer period of time. Since details of these means do not form a part of the present invention, these means are shown only diagrammatically. Actually, these switch means are quite complicated switching arrangements which, however, are entirely known and therefore do not require a further detailed description. The switch means Wa is in its simplest form a push-button switch that can be operated mechanically or by hand and is normally in closed position so as to be moved into open position only when an arming signal is to be given. As long as this switch means Wa remains in closed position, the connecting wire Da remains connected in parallel with the return line connection Dr and in this manner serves also as a return line connection, indicated by the dotted arrow 1. However, as soon as the switch Wa is moved into open position, the wire Da acts as a signal conducting wire and only in this case an arming signal Ua, indicated by the dotted arrow II, is transmitted to the missile or generated therein for the purpose of moving the safety control means into its arming position.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of remote control systems differing from the types described above.

While the invention has been illustrated and described as embodied in the remote control systems for missiles containing an explosive charge and a detonator device therefor, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a remote control system for missiles containing at least one explosive charge, in combination, electrically operable detonator means in said missile, said detonator means including electrically ignitable detonator cap means in detonating proximity with said charge; electric circuit means connected to said detonator means for operating the latter and including a source of electrical energy for actuating said detonator means; safety control means in operative proximity with said detonator means and comprising a shielding means movable between a nonarming position in which said shielding means is positioned between said detonator cap means and said charge and in which it renders said circuit means inoperable, and an arming position in which it renders said circuit means operable for actuating said detonator means and in which said detonator cap means, if ignited, is free to act on said charge, and electrical actuating means for moving said shielding means into said arming position, said safety control means including bias means for normally urging said shielding means into said non-arming position, and transducer means for receiving an arming signal and for causing energization of the electrical actuating means of said safety control means for moving said shielding means into said arming position upon receiving said arming signal.

2. In a remote control system for missiles containing at least one explosive charge, in combination, electrically operable detonator means in said missile, said detonator means including electrically ignitable detonator cap means in detonating proximity with said charge, and impactresponsive actuator means; electric circuit means connected to said detonator means for operating the latter and including a source of electrical energy for actuating said detonator means, and a series-combination of normally open actuating switch means and normally open safety switch means, said actuating switch means being movable into closed position by said actuator means upon impact; safety control means in operative proximity with said detonator means and comprising a shielding means movable between a non-arming position in which said shielding means is positioned between said detonator cap means and said charge and in which said safety switch means is in its normal open position, and an arming position in which said safety switch means is moved into closed position by said shielding means for actuating said detonator means and in which said detonator cap means, if ignited, is free to act on said charge, and electrical actuating means for moving said shielding means into said arming position, said safety control means including bias means for normally urging said shielding means into said non-arming position; and transducer means for receiving an arming signal and for causing energization of the electrical actuating means of said safety control means for moving said shielding means into said arming position upon receiving said arming signal.

3. In a remote control system as claimed in claim 1, transistor means connected in said circuit means for acting as switch means for energizing said electrical actuating means, said transistor means being normally non-conductive, and being rendered conductive by said transducer means upon receiving of an arming signal.

4. In a remote control system as claimed in claim 3, said transducer means comprising amplifier means for converting an alternating current arming signal into a direct current voltage and for supplying said direct current voltage to said transistor means so as to render the latter conductive.

5. In a remote control system as claimed in claim 3, a control installation in circuit connection with said missile, said control installation comprising means for transmitting to said missile via said connection two separate series of time-modulated pulses and means for phase-shifting said series of pulses, the phase shifted condition constituting said arming signal, and said transducer means including means for deriving from said series of pulses, if received in phase-shifted condition, a direct current voltage and for supplying the latter to said transistor means so as to render the latter conductive.

6. In a remote control system for a missile containing an explosive charge and a detonator device therefor, in combination,

shield means movably positioned between said detonator device and said explosive charge in operative proximity with said detonator device; shield moving means in operative proximity with said shield means and upon electrical energization thereof adapted to move said shield means to a non-arming position in which said shield means is positioned between sad explosive charge and said detonator device and upon electrical deenergization thereof, said shield means being adapted to move to an arming position in which it is spaced from and independent of said detonator device and said explosive charge; detonator actuating means comprising a circuit arrangement including said detonator device, a source of electrical energy, said shield moving means and switch means connected together in a manner whereby electrical energization of said switch means closes the said switch means and causes electrical energization of said detonator device and of said shield moving means; and

means for applying an arming signal to said switch means to close the said switch means.

7. In a remote control system for a missile as claimed in claim 6, a first auxiliary switch connected in said circuit arrangement in a manner whereby when said first auxiliary switch is open it causes electrical deenergization of said detonator device and when the said first auxiliary switch is closed it causes electrical energization of the said detonator device, said first auxiliary switch being positioned in operative proximity with said shield means in a manner whereby when the said shield means is moved to its arming position it causes the said first auxiliary switch to close and when the said shield means is moved to its non-arming position it causes the said first auxiliary switch to open.

8. In a remote control system for a missile as claimed in claim 7, a second auxiliary switch connected in said circuit arrangement in series with said first auxiliary switch in a manner whereby when said first and second auxiliary switches are open they cause electrical deenergization of said detonator device and when the said first and second auxiliary switches are closed they cause electrical energization of the said detonator device, said second auxiliary switch being adapted to remain normally open and to close on impact of said missile with an object.

References Cited in the file of this patent UNITED STATES PATENTS 1,623,475 Hammond Apr. 5, 1927 2,603,433 Nosker July 15, 1952 2,983,800 Rabinow May 9, 1961 

1. IN A REMOTE CONTROL SYSTEM FOR MISSILES CONTAINING AT LEAST ONE EXPLOSIVE CHARGE, IN COMBINATION ELECTRICALLY OPERABLE DETONATOR MEANS IN SAID MISSILE, SAID DETONATOR MEANS INCLUDING ELECTRICALLY IGNITABLE DETONATOR CAP MEANS IN DETONATING PROXIMITY WITH SAID CHARGE; ELECTRIC CIRCUIT MEANS CONNECTED TO SAID DETONATOR MEANS FOR OPERATING THE LATTER AND INCLUDING A SOURCE OF ELECTRICAL ENERGY FOR ACTUATING SAID DETONATOR MEANS; SAFETY CONTROL MEANS IN OPERATIVE PROXIMITY WITH SAID DETONATOR MEANS AND COMPRISING A SHIELDING MEANS MOVABLE BETWEEN A NONARMING POSITION IN WHICH SAID SHIELDING MEANS IS POSITIONED BETWEEN SAID DETONATOR CAP MEANS AND SAID CHARGE AND IN WHICH IT RENDERS SAID CIRCUIT MEANS INOPERABLE, AND AN ARMING POSITION IN WHICH IT RENDERS SAID CIRCUIT MEANS OPERABLE FOR ACTUATING SAID DETONATOR MEANS AND IN WHICH SAID DETONATOR CAP MEANS, IF IGNITED, IS FREE TO ACT ON SAID CHARGE, AND ELECTRICAL ACTUATING MEANS FOR MOVING SAID SHEILDING MEANS INTO SAID ARMING POSITION, SAID SAFETY CONTROL MEANS INCLUDING BIAS MEANS FOR NORMALLY URGING SAID SHIELDING MEANS INTO SAID NON-ARMING POSITION, AND TRANSDUCER MEANS FOR RECEIVING AN ARMING SIGNAL AND FOR CAUSING ENERGIZATION OF THE ELECTRICAL ACTUATING MEANS OF SAID SAFETY CONTROL MEANS FOR MOVING SAID SHIELDING MEANS INTO SAID ARMING POSITION UPON RECEIVING SAID ARMING SIGNAL. 